1. Field of the Invention
The present invention relates to image processing apparatuses and methods, and programs. More specifically, the present invention relates to the present invention relates to an image processing apparatus and method and a program with which it is possible to discriminate an object in each local area in an image.
2. Description of the Related Art
Recently, digital cameras, camcorders, security cameras, and so forth equipped with object recognition functions are available. Applications of object recognition range greatly, including control of exposure, white balance, and auto focus (AF) optimal for an object, face detection, and tracking of an object.
As a method of face recognition, a method of recognizing a face by using a spatial gradient of luminance or the like exists. In this method, a human face is recognized by using a spatial feature of the human face.
As a method of skin color recognition, a method exists in which color information represented in the RGB (red, green, and blue) color space is converted into color information represented in the HSV (hue, saturation, and brightness) color space for recognition of skin color. Since the hue H and the brightness V are independent in the HSV color system, it is possible to check hue without being affected by brightness of a picture. Thus, by specifying a certain range of hue H in the HSV color space, it is possible to specify skin color without being affected by brightness or the like.
Furthermore, there has been proposed a method in which an extended chromatic point of an object is calculated on the basis of information acquired by an imaging element having spectral sensitivity for four colors including luminance Ye in addition to the RGB three primary colors, and an object is discriminated by comparing a distance with an extended chromatic point of a known object. (See Japanese Unexamined Patent Application Publication No. 2003-030646.) As opposed to a chromatic point calculated on the basis of color signals of the RGB three primary colors, which is a two-dimensional value, the extended chromatic point based on the four colors of RGB and Ye is a three-dimensional value, so that the accuracy of object discrimination is improved.